Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study

Area of Science:

• Virology
• Dermatology
• Nutritional Science

Background:

• Herpes simplex virus (HSV) causes recurrent herpes labialis (cold sores).
• L-lysine demonstrates in vitro antiviral properties against HSV.
• Prophylactic use of L-lysine for recurrent HSV infections requires clinical evaluation.

Purpose of the Study:

• To assess the prophylactic efficacy of daily L-lysine monohydrochloride in preventing recurrent herpes simplex labialis.
• To evaluate the effect of L-lysine on lesion healing and severity.

Main Methods:

• A double-blind, placebo-controlled, crossover study involving 65 patients with recurrent herpes labialis.
• Patients received 1000 mg of L-lysine daily for 12 weeks, followed by placebo for 12 weeks, or vice versa.
• Recurrence rates, healing times, and lesion appearance were monitored.

Main Results:

• Overall, L-lysine prophylaxis did not significantly alter the recurrence rate of herpes simplex labialis.
• A statistically significant higher proportion of patients were recurrence-free during L-lysine treatment compared to placebo (p = 0.05).
• L-lysine did not impact the rate of lesion healing or the severity of herpes lesions.

Conclusions:

• Daily L-lysine monohydrochloride (1000 mg) showed no overall effect on herpes simplex labialis recurrence.
• A subset of patients may experience reduced recurrence rates with prophylactic L-lysine.
• Further research is warranted to identify patient subgroups who may benefit from L-lysine supplementation for HSV prevention.